Natalie Sherman
New York economic journalist

As we just reported in the article below, polls indicate the presidential election remains too close to call, but Donald Trump told crowds he has the wind at his back.

His proof? Odds on betting sites, such as Polymarket, Kalshi and PredictIt, all place him strongly in favor of winning.

Proponents of these sites view them as efficient marketplaces, capable of quickly assimilating new information. Researchers say the track records of betting markets hold up to scrutiny as well as other prediction tools.

Skeptics note that those betting are somewhat of a self-selecting crowd and have raised questions about the risk of market manipulation.

On New York-based Polymarket, for example, US citizens are technically banned and betting is done in crypto.

Fortune reported that some analysts who track Polymarket’s activity are seeing signs of “wash trading” — when the same people buy and sell repeatedly, giving an exaggerated sense of activity on the platform.

And while some sites have rules, such as limits on bet sizes, at Polymarket a few big bets can tip the scales. This year, Polymarket said four accounts from a single French trader were responsible for the market move.